Aubrey, Henry G.
Coexistence: economic challenge and response
National Planning Association, 1961
 Buku Teks
Janda, Kenneth
The challenge of democracy : government in America 1999-2000 update
Houghton Mifflin, 2000
 Buku Teks
The challenge of democracy American government in global politics
Kenneth Janda, Jeffrey M. Berry, Jerry Goldman, Deborah J. Schildkraut, Paul Manna
Cengage Learning, 2018
 Buku Teks
Jerker B. Svantesson
Trans-Atlantic data privacy relations as a challenge for democracy
Intersentia, 2018
 eBooks
Rosen, George
Democracy and economic change in India
University California Press, 1966
 Buku Teks